The disadvantages of the conventional reciprocating piston compressors and pumps are well-known: low ratio of power developed to machine mass and relatively low mechanical efficiency. The same holds true also for conventional rotary-laminar and screw compressors and pumps.
While V-type engines have a higher power/mass ratio, such designs as the Wankel engine have serious sealing problems even today.
There exists a rotary vane machine (U.S. Pat. No. 5,366,356) which comprises stationary end members connectable to one another, a rotor body rotating at uniform speed and having two first vanes, and two second vanes driven by the rotor body via a system of levers controlled by a camming mechanism, due to which the second vanes rotate at a periodically increasing and periodically decreasing speed. The serious disadvantage of this machine resides in the fact that the lever system making up the kinematic connection between the two types of vanes constitutes considerable inertial masses carrying out nonsymmetrical movements over large angular ranges, generating inertial forces exceeding the working load of the machine. The ensuing vibrations and noise preclude the construction of machines rotating at higher speeds.